Plan to slow down the spread of the Sahara Desert-planting gardens


This story originally Appear in Atlas Obscura And is Climate Service Desk cooperate.

From the air, the new garden in the town of Boki Diawe in northeastern Senegal looks like an eye: open wide, unblinking, flanked by scattered turf dug out of the surrounding soil, as black as freckles on the nose. The ground was still sandy brown, but not far away, it was a bright green.

If everything goes according to plan, this garden will soon look equally lush.Round garden-known locally Toluker——Papaya, cashew nuts, lemons, etc. have been planted recently.The inner curved row is dedicated to medicinal plants, while the outer row is lined with baobabs and Kaya senegal, Its wood is also called African Mahogany.

The garden is the latest version of the project, called Green Great Wall, Originally conceived as a green belt winding thousands of miles in the Sahel region from Senegal to Djibouti. Initiated by the African Union in 2007 Support comes from The European Union, the World Bank and the United Nations, the project was originally designed to help Stop the Sahara Desert from drifting south and avoid desertification.

Desertification is the process of degrading dense land into desert. Chukwuma J. Okolie, lecturer in surveying and geoinformatics at Lagos University in Nigeria, said that this phenomenon is driven by “the interaction of natural and human factors.” Okolie uses remote sensing data (such as satellite imagery) to track landscapes sloping toward desert conditions.

The driving factors of desertification include climate variability and climate change, overgrazing, construction of river dams, and conflicts that displace people and stimulate land-use conversion. Long-term drought will make fertile soil fragile, while wind and rain will make it disappear. “Deforestation can accelerate this process because trees can act as windbreaks,” Occoli said. This is the origin of the concept of the Great Green Wall.

The original plan emphasized trees as anchor points for the soil and buffers against sand erosion. Geert Sterk, a geoscientist at Utrecht University who studies land degradation, said that certain elements of this idea make sense. “The roots of trees and shrubs hold the soil, and the canopy intercepts raindrops and reduces strong winds before reaching the soil surface,” curbing wind erosion and erosion in the area Relatively rare but heavy rain, Sterk explained in an email.

But the ambitious plan has not really been realized. There are political debates about where the green line should be drawn, scientific debates about what contributes to desertification and the effectiveness of this method.As of 2021, the project Just a small part of achieving the goal Planting hundreds of millions of mu.

New injection of funds, Promised earlier this year The cooperation between governments and development banks will promote the project-now, the focus is shifting to more local gardens. In the past seven months, more than 20 versions of circular gardens have appeared across Senegal.

Aly Ndiaye, a Senegal-born agricultural engineer, he helped design Toluker, Tell Reuters The Great Green Wall should consist of “permanent, useful and continuous” smaller, prolific gardens, a series of practical plots rather than a row of uninterrupted trees. Okolie agrees that the project cannot push any seedlings underground. He said that this must include “striving to find the best species that can thrive under the given soil conditions and climate,” while also attracting those who are willing to nurture them.Researchers have discovered When the focus is only on planting trees and the locals are excluded, agroforestry projects often fail. “When the government planted trees, people in the community would feed them,” Okolie said. “The community must have ownership.”


Source link